Circuit breakers



Aug. 21, 1956 H. A. HUMPAGE CIRCUIT BREAKERS 2 Sheets-Sheet 1 OriginalFiled May 24, 1945 IN V EN TOR.

38 647mm) ALanr H p5 2 Sheets-Sheet 2 H. A. HUMPAGE CIRCUIT BREAKERSAug. 21, 1956 Original Filed May 24, 1945 INVENTOR. 70 l /lmowALJIMf/UMPAGE' BY 64* M F A 1-roe-5ys H AD 4 3 96 50 United StatesPatent Gfifice 2,760,029 Patented Aug. 21, 1956 CIRCUIT BREAKERS HaroldA. Humpage, Eioomfield, N. J assignor, by mesne assignments, to FederalElectric Products Company, Newark, N. .L, a corporation Application July31, 194$, Serial No. 41,837, new Patent No. 2,647,191, dated July 28,1953, which is a division of application Serial No. 595,556, May 24,1945, now Patent No. 2,459,427, dated January 18, 1949. Divided and thisapplication April 27, 1953, Serial No. 351,267

6 Claims. (Cl. 200-116) This invention relates to automatic circuitbreakers, and more particularly to circuit breakers of the type whichare used for house lighting and other low amperage circuits.

The primary object of the invention is to provide a circuit breakermechanism constituting a unit and comprising a housing in which saidunit is mounted, the mechanism unit and the housing being so constructedand related that the mechanism unit can be calibrated and tested beforebeing placed in the housing and so that the assembly of the mechanismunit in the housing is facilitated.

Another object of this invention is the provision of a multi-polecircuit breaker comprising a housing in which a plurality of circuitbreaker mechanism units, one for each pole, are disposed for independentoperation, the construction and arrangement of the housing and mechanismunits being such that they can be interchangeably positioned within thehousing.

A further object of the invention is the provision of a circuit breakercomprising a housing for the circuit breaker mechanism having meansformed in the housing as an integral part thereof for guiding themovable contact member.

A yet further object of the invention is generally to provide animproved small and inexpensive circuit breaker which is well adapted tobe used, with reliability of operation, for house lighting and other lowamperage circuits in lieu of a switch and fuse combination.

The above and other objects, features and advantages of the presentinvention will be fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings:

In the drawings:

Fig. 1 is a front view of a circuit breaker embodying the presentinvention;

Fig. 2 is a side view thereof;

Fig. 3 is a rear view thereof;

Figs. 4 and 5 are end views as seen from lines 4-4 and S-5 respectivelyof Fig. 2;

Fig. 6 is a side view of the circuit breaker, one part of the housingbeing removed, the movable contact members of the circuit breakermechanism being in their open positions;

Fig. 7 is a view of the left hand part of the housing, as illustrated inFig. 6, and of the circuit breaker mechanism, showing the movablecontact member in its closed position;

Fig. 8 is a sectional view on the line 8-8 of Fig. 7;

Fig. 9 is a sectional View on the line 99 of Fig. 7;

Fig. 10 is a sectional view on the line 10-10 of Fig. 7;

Fig. 11 is a perspective view of a magnetic member forming a part of acircuit breaker mechanism;

Fig. 12 is an end view of a combined terminal and stationary contactmember of one type;

Fig. 13 is a bottom view of a combined terminal and stationary contactmember of another type.

Referring now to the drawings in detail, the circuit breaker of thepresent invention comprises a two part insulation casing or housing 10formed of two identical or symmetrical parts 12, each of said partsbeing formed of insulation material preferably by a molding operation.Each casing part 12 forms one-half of the housing, the two casing partsbeing secured in housing defining relation in any suitable way, forexample by bolts 14, the front and rear facing edges 16 and 18, the endfacing edges 20 and the intermediate facing edge 22 of the two casingparts 12 being in abutting surface to surface relation. Said facingedges are formed on the thickened edge portions at the inner orconfronting sides of the opposed side walls of the housing, saidthickened edge portions of said side walls extending peripherally of thehousing. Thus, each casing part is formed with two recesses 24 whichdefine two chambers for two circuit breaker mechanisms. It will beunderstood, however, that the housing can be provided for a single polebreaker in which case it can have a single chamber, in lieu of the twochambers for the multi-pole circuit breaker illustrated herein. Eachcasing part 12 is provided at its opposite ends with open recessedportions 26 which form arcing chambers and in which terminal members andthe stationary contacts of the two circuit breaker units are positionedrespectively. The arcing chambers formed by the recesses 26 provided inthe companion casing parts 12 are indicated at 28 in Figs. 4 and 5. Thefront of each casing part is provided with recessed portions whichdefine openings 33 through which the handles 32 project for manualoperation of the circuit breaker mechanisms. Each of said handles isfixed to pivot pin 34, the opposite ends of which are received inbearing recesses 36 (Fig. 8) formed in the companion casing parts 12.

Referring now to the circuit breaker mechanisms, which are disposed inthe companion chambers in housing 10, each of said mechanisms is of thesame construction and includes a manually operable member, here shown asthe abovementioned pivoted handle 32. A movable contact member 38,formed in one piece of sheet metal of suitable thickness, is mounted inthe chamber for pivotal movement by pivot pin 40, the opposite ends ofwhich are received in aligned bearing recesses 41 in the companioncasing parts 12. Said movable contact member 33 is provided at one endthereof with a contact 42 which is engageable with and disengageablefrom a companion stationary contact 44 carried by a terminal member 46or by a terminal member 48 both of which will hereinafter be moreparticularly described. The casing 10 is provided with means for guidingmovable contact member 33, for which purpose the thickened or inwardlyprojecting end portions 43 of the companion casing parts 12 are providedwith recessed portions 45 which define a guide slot 47 (Figs. 9 and 10)through which an end portion 49 projects with slight clearance. Thus, itwill be noted that the means for guiding the movable contact member ofeach circuit breaker mechanism is formed in the casing as integral partsthereof. A thermal-current responsive member 5% which, as here shown,consists of a thermostatic bi-metallic flexible strip, is welded orotherwise secured at one end thereof to a side edge of movable contactmember 38. The free end of bi-metallic strip is arranged to releasablyengage the end of one arm of a lever 52 pivotally mounted on the end ofmovable contact member 38 opposite to the end which carries the contact42, said lever 52 being preferably insulated from the movable contactmember in any suitable Way, for example, as shown in Fig. 7 ofChristensen Patent No. 2,209,319. The other arm of lever 52 is connectedto the companion handle 32 by a resilient link 5'4, one end of whichpasses with slight clearance through an opening 56 in said arm and theother end of which is pivotally engaged with the adjacent end of saidhandle. As clearly shown in the drawings, each movable contact member 38is provided with a laterally ofiset portion 58 so that each circuitbreaker mechanism can comprise a movable contact member of the sameconstruction as well as other parts of the same construction and bemounted interchangeably in either of the mechanism chambers of thecasing. A coil spring 60 is operatively interposed between the movablecontact member 38 and the companion handle 32 for biasing the movablecontact member to its open position. One end of said spring engages alug 62 fixed to handle 32 and the other end of said spring en gages alug 64 integral with the companion movable contact member 38. Themechanism constituted by handle 32, movable contact member 38, thermalstrip 50, lever 52 and link 54 is similar to and operates substantiallyin the same way as corresponding mechanism in the circuit breakerdisclosed in said Christensen Patent No. 2,209,319. Also as here shownthe movable contact member 38 is provided with a slot 64 and a taperedscrew 66 for calibrating the circuit breaker as shown and described insaid Christensen patent. It will be understood that the member t)operates to latch the manually operable actuating mechanism to themovable contact member and to unlatch the actuating mechanism from themovable contact member, the unlatching taking place by deflection ofmember 50 from engagement with lever 52 upon the occurrence of anoverload or under other abnormal predetermined current conditions in thecircuit controlled by the circuit breaker. When member 50 is deflectedfrom engagement with the companion lever 52, spring 60 is efiective tomove contact member 38 to its open position, i. e., from the positionillustrated in Fig. 7 to the position illustrated in Fig. 6. It Will benoted that the inner end 47A of the guide slot 47 constitutes a stop formember 38 to limit the opening movement of the latter. The intermediatethickened wall portion 49 of each casing part 12 terminates short of therear wall of the casing to provide a recess into which levers 52 aremovable, as shown in Fig. 6, and to provide shoulders 53 which serve asstops for said levers, respectively.

The thermal element 50 is connected in series with movable contactmember 38 and the circuit which is to be controlled by the circuitbreaker. For this purpose a flexible metallic conductor or connector 68is connected to said thermal element, preferably adjacent the free endthereof, and to a companion terminal member 70. There are two terminalmembers 70, one for each of the two thermal members 50 of the twocircuit breaker mechanisms. These two terminal members 70 are positionedin the recess below intermediate casing portions 49, and aremechanically and electrically connected preferably removably, to acommon lead or bus bar 72 in any suitable way as by a screw 74 whichpasses through aligned apertures in said terminal members 70 and isthreaded into a tapped hole in bus bar 72. An opening 76 is provided inthe back of casing for access to screw 74. The lead or bus bar 72 entersthe casing through a slot 78 in the side thereof. Said slot is providedin each of the companion casing parts 12. Thus, the terminal lead or busbar 72 can be long enough to project into a plurality of casings 10which may be disposed with their respective side walls in adjacent orabutting side by side relation. The outer portion of bus bar 72 isprovided with a terminal member 80. It will be noted that the provisionof the separate individual terminals 70 for the two circuit breakermechanisms provides for independent calibration and testing of thedifferent circuit breaker mechanisms and also provides for differentcurrent carrying capacities of the two circuit breaker mechanisms,respectively. Thus, while the two circuit breaker mechanisms are mountedin a common housing, they can be of different current carryingcapacities or ratings, although, of course, they can have the samecurrent carrying capacities or ratings. As here shown, the circuitbreaker mechanisms are illustrated .4 for different current carryingcapacities as indicated by the different terminal members 46 and 48 forthe two in dependently operable circuit breaker mechanisms,respectively. More particularly the circuit breaker mechanism at theright of the casing, as illustrated in Fig. 6 is designed for a highercurrent carrying capacity than the other circuit breaker mechanism andfor that purpose the terminal member 46 for said first mentioned circuitbreaker mechanism has a higher current carrying capacity than theterminal member 48 for the other circuit breaker mechanism. Also it willbe noted that the terminal members 70 when secured to the bus bar 72internally of the housing hold the latter in stationary positions, sincesaid terminal members are positioned in the space between confrontingwall portions of the housing with the edges of said terminal membersabutting or closely adjacent the inner surfaces of said adjacentportions, respectively, of the housing.

The casing 10 is constructed to hold the terminal members 46 and 48 insuch manner as to obviate the need for screws or other fastening means.For this purpose the casing 10 is provided with aligned recesses 82formed in the companion casing parts 12 to receive either theprojections 83 of the terminal member 46 or the projections 84 of theterminal member 48. In addition to the recesses 82, casing 10 isprovided at each end thereof with aligned recess 86 formed in the twocasing parts 12 to receive an end portion 88 of the member 48. It willbe noted therefore, that the casing is constructed and arranged so thateither terminals such as 46 or terminals such as 48 can be mounted andsecured at both ends of the casing or, as here shown, a terminal such as46 can be mounted and secured at one end of the casing and a terminalsuch as 48 can be mounted and secured at the opposite end of the casing.It will be understood that when the terminals are positioned with theirprojecting portions 83 or 84, as the case may be, in the companionrecesses 82 and the two casing parts are fastened together by the bolts14, or in any other suitable manner, with their inner faces in abuttingrelation, the terminal members are securely held or fastened to thecasing, in positions between the opposite side walls thereof, thuseliminating the use of extraneous fastening devices. It will be notedthat, as here shown, members 46 and 48 carry the stationary contacts 44,which are preferably welded thereto, and thus constitute combinedterminal and stationary contact members, and that when said combinedmembers are mounted on the casing said stationary contacts are disposedin the respective arcing chambers in position to be releasably engagedby the contacts 42 of the companion movable contact members 38,respectively.

The thermal current responsive member 5?; is operable not only inresponse to the heating effect of the current passing therethrough, butis also operably under the control of electro magnetic means foreffecting disengagement of the companion relatively movable contacts 42and 44, and the arrangement is preferably such that as here shown theelectro magnetic means is energized by the current which passes throughthe thermal current responsive member 50. For this purpose an electromagnetic member 90 is mounted on member 50 near the free end thereof anda companion rigid armature 92 is disposed in spaced confronting relationto electro magnetic member 90. As clearly illustrated in the drawings,the inner end 94 of armature 92 is fixed, preferably by welding, to thefixed end of thermal member St. The electro magnetic member 90 issecured to the thermal member 50 by lateral projections 96 which areintegral with thermal member 50 and which project through openings 98 inthe companion electro magnetic member 90. Preferably, openings 98 aresomewhat larger than the companion provisions 96 to allow relativemovement between thermal member 50 and electro magnetic member 90 so asto maintain the parallel relation between the confronting portions ofmember 90 and the companion armature 92 without impairment by thedeflection or flexing of thermal member 50. As shown in the drawings,magnetic member 90 straddles the member 50 by which it is carried. Saidmenrber 90 is formed in one piece of soft sheet steel or other suitablesheet metal and is provided with an end wall, opposed side walls inwhich the openings 98 are provided, and with outturned end portions 99(Fig. 11) which are arranged in surface-confronting relation to theadjacent surf-ace of armature 92. Openings 98 are positioned so thatsaid end wall of member 9%} is spaced from member 50, and there is aslight clearance between the edges of member '0 and the inner surfacesof the side walls of member 90 so that the latter has a free relativemovement on member 50. it will be understood that upon the occurrence ofan overload in excess of that for which the circuit breaker is designedto open under the control of the thermal member 59 by flexing of thelatter in response to the heating thereof, the electro magnetic deviceis operable instantaneously to effect, disengagement of the companioncontact members. It will be understood that upon the occurrence of suchexcess over-load the magnetic attraction between members 90 and 92results in the deflection of thermal strip 50 for disengaging the latterfrom the companion arm of the lever 5'2, and in this connection it willbe understood that since member 92 is rigid and thermal member 50 whichcarried member 90 is flexible, member 90 is movable by magneticattraction toward member 92, thus deflecting or unlatching thermalmember 50 from the companion lever 52.

The housing 10 is provided with means to enable it to be secured to asupporting plate, panel, or other support. For this purpose the casingparts 12 are provided with recesses mil in which nuts 102 fit and areheld against rotation by the side walls of the recesses. Holes 1M areprovided at the back of the housing for screws (not shown) which engagenuts M82.

This is a division of my application Serial No. 41,837, now UnitedStates Patent No. 2,647,191, which is a division of my application whichmatured into United States Patent No. 2,459,427, now Uni-ted StatesPatent No. Re. 23,188.

While I have shown and described the preferred embodiment of myinvention, it will be understood that the latter may be embodiedotherwise than as herein specifically illustrated or described and thatin the illustrated embodiment certain changes in the details ofconstruction and in the arrangement of parts may be made withoutdeparting from the underlying ideas or principles of the inventionwithin the scope of the appended claims.

I claim:

1. In an automatic circuit breaker comprising a bone ing, a plurality ofindependently operable circuit-breaker mechanism units mounted in saidhousing, each of said units including a movable contact member and aflexible thermostatic strip for effecting the circuit-opening movementof the movable contact member, a plurality of flex ible connectors eachsecured at one end thereof to said thermostatic strips, respectively,individual terminal members secured to the opposite ends of saidflexible connectors, respectively, said casing having opposed side Wallportions defining a recess in which said terminal members are positionedand at least one of said side wall portions having a slot therethrough,a bus bar removably positioned in said slot and projecting therethroughfrom the exterior of said housing into said recess, and means removablysecuring said individual terminal members to said bus bar in said spacein electrically connected relation to said bus bar, said terminal menrbers secured to said bus bar providing means for holding said bus bar inposition in said slot.

2. In an automatic circuit breaker comprising a housing, a plurality ofindependently operable circuit-breaker mechanism units mounted in saidhousing, each of said units including a movable cont-act member and aflexible thermostatic strip for effecting the circuit-opening movementof the movable contact member, a plurality of flexi ble connectors eachsecured at one end thereof to said thermostatic strips, respectively,individual terminal members secured to the opposite ends of saidflexible connectors, respectively, said casing having opposed side wallportions defining a recess in which said terminal mem' bers arepositioned and at least one of said side wall portions having a slottherethrough, a bus bar removably positioned in said slot and projectingtherethrough from the exterior of said housing into said recess, andmeans removably securing said individual terminal members to said busbar in said space in electrically connected relation to said bus bar,said terminal members secured to said bus bar providing means forholding said bus bar in position in said slot, said housing consistingessentially of two symmetrical parts formed of insulation material, eachof said parts having a side Wall, a thickened end portion, thickenedupper and lower edge portions, and an intermediate thickened portionabutting the corresponding portions, respectively, of the other sidewall and thereby defining two chambers, one for each of said mechanisms,said intermediate thickened portions being spaced from the lower edgeportions and defining a space in which said terminal members arepositioned, said lower edge portions having comp lernental recessesdefining an opening in line with said intermediate portions defining anopening for access to said securing means.

3. In an automatic circuit breaker comprising a housing, a plurality ofindependently operable circuit-breaker mechanism units mounted in saidhousing, each of said units including a movable contact member and aflexible thermostatic strip for effecting the circuit-opening movementof the movable contact member, a plurality of flexible connectors eachsecured at one end thereof to said thermostatic strips, respectively,individual terminal members secured to the opposite ends of saidflexible connectors, respectively, said casing having opposed side wallportions defining a recess in which said terminal members are positionedand at least one of said side wall portions having a slot therethrough,a bus bar removably positioned in said slot and projecting therethroughfrom the exterior of said housing into said recess, and means removablysecuring said individual terminal members to said bus bar in said spacein electrically connected relation to said bus bar, said terminalmembers secured to said bus bar providing means for holding said bus barin position in said slot, portions of said side walls between saidrecesses being thickened and disposed in abutting relation and spacedfrom the bottom of said housing, the lower ends of said intermediateportions forming stops for certain movable parts of said circuitbreaker, said terminal members being disposed between said side walls inthe space below said intermediate thickened portions.

4. In an automatic circuit breaker, a housing for a circuit breakermechanism, said housing having opposed spaced side walls, terminal meansfor the circuit breaker mechanism positioned in said housingintermediate the opposite ends thereof, and a bus bar extendingtransversely of said housing, said bus bar being electrically connectedto said terminal means, and said bus bar being positioned and located insaid transverse disposition thereof in the side walls of the housing byformations in said side walls, which are complementary to said bus bar.

5. An automatic circuit breaker as defined in claim 4. furthercharacterized in that said formations constitute a slot defined in eachof the side walls of the housing, said slot being in registry, and saidbus bar is mounted in said slots to effect said positioning and locationthereof.

6. An automatic circuit breaker as defined in claim 4, furthercharacterized in that said formations constitute a slot as defined ineach of the side walls of the housing, said slots being in registry, andsaid bus bar is mounted in said slots to effect said positioning andlocation thereof, said circuit breaker mechanism including a pluralityof independently operable circuit-breaker mechanism units each providedwith an individual terminal member, and said terminal members beingsecured to said bus bar for holding the latter in position in saidslots.

References Cited in the file of this patent UNITED STATES PATENTSChristensen July 30, 1940 Wolf et al. Feb. 10, 1942 Johnson June 22,1943 Christensen June 27, 1944

